1. Field of the Invention
This invention relates in general to container screw-on closure devices and in particular to such closure devices which are designed to be tamper-proof.
2. Description of the Prior Art
There are various container caps and seals which attempt to provide for the enclosing and sealed retention of the particular contents within the container. Of course, the specific container design will control to a significant degree the type of cap or seal which can be used. One type of cap which is widely used is the solid, screw-on design such as found in supermarkets on glass, plastic and metal containers. Some of these caps, such as those on beverage bottles, are intended to be resealable and have a metal ring secured to the bottle and connected to the cap portion by means of a perforated seam. When the cap is turned in a counterclockwise direction in an attempt to unscrew the cap from the bottle, the perforations tear and the cap is removable. Cap designs of this type with retaining means prevent the cap from loosening due to vibrations which may occur during shipment.
Larger containers such as those used in the transport and storage of chemicals and industrial solutions, represent a different style of construction. Such containers have pour spout openings or the like which may be from two to four inches in diameter or larger and this size is not suitable for the metal perforated design previously described because of the torque required in order to tear the perforated seam and for other reasons. Often such containers are sealed with conventional screw-on caps which are retained in their screwed-on position by means of wire tagging which secures the cap to some anchor point on the container. This particular process is somewhat time consuming to perform and requires that suitable anchor points be added to the container. When the container is designed for transport or storage of a particular solution, the container material may be important so that the container will not contaminate its contents nor be adversely affected by the contents. Blow-molded plastic containers are widely used, but due to the flexibility of the material and thus of the spout opening, securely sealing this opening presents certain problems in the design and construction of retained and sealed closure devices.